If you're following almost any recipe, there's a very good chance that you'll need to measure out your ingredients. It makes a big difference to get it right when you're cooking. It's even more important when you're baking.
Eye balling your measurements might work for the pros, but if you're just beginning your kitchen experimentation, don't take chances. Get yourself a set of measuring cups. More, invest in a strong, long-lasting stainless-steel set like these. There's simply no point in going for cheap plastic cups from the dollar store unless you're really broke. These measuring cups from RSVP are more than just good looking; they've also got extra long handles to help you dig into the bottom of containers.
By the way, when you measure dry ingredients, you're meant sift first and then measure unless the recipes calls for a different order or technique. Never pack ingredients in measuring cups unless specifically told to do so.